using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/66581597/json-property-name-as-whole-json-path-to-the-property

​

    public class Person

    {

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public Address Address { get; set; }

    }

​

    public class Address

    {

        public string Street { get; set; }

        public string StreetNumber { get; set; }

    }

​

    public static partial class JsonExtensions

    {

        // Copied verbatim this answer

        // https://stackoverflow.com/a/47269811/3744182

        // By https://stackoverflow.com/users/10263/brian-rogers

        // To https://stackoverflow.com/questions/47267542/rename-jproperty-in-json-net

        public static void Rename(this JToken token, string newName)

        {

            if (token == null)

                throw new ArgumentNullException("token", "Cannot rename a null token");

​

            JProperty property;

​

            if (token.Type == JTokenType.Property)

            {

                if (token.Parent == null)

                    throw new InvalidOperationException("Cannot rename a property with no parent");

​

                property = (JProperty)token;

            }

            else

            {

                if (token.Parent == null || token.Parent.Type != JTokenType.Property)

                    throw new InvalidOperationException("This token's parent is not a JProperty; cannot rename");

​

                property = (JProperty)token.Parent;

            }

​

            // Note: to avoid triggering a clone of the existing property's value,

            // we need to save a reference to it and then null out property.Value

            // before adding the value to the new JProperty.  

            // Thanks to @dbc for the suggestion.

​

            var existingValue = property.Value;

            property.Value = null;

            var newProperty = new JProperty(newName, existingValue);

            property.Replace(newProperty);

        }       

    }

​

​

    class TestClass

    {

        public static void Test()

        {

            var person = new Person

            {

                FirstName = "Homer",

                LastName = "Simpson",

                Address = new () 

                {

                    Street = "Evergreen Terrace",

                    StreetNumber = "742",

                },

            };

            var settings = new JsonSerializerSettings

            {

                ContractResolver = new CamelCasePropertyNamesContractResolver(),

            };

            var jObject = JObject.FromObject(person, JsonSerializer.CreateDefault(settings));

            foreach (var item in jObject.Descendants().OfType<JProperty>().Select(p => (Property: p, p.Path)).ToList())

            {

                // The Rename extension method from https://stackoverflow.com/a/47269811/3744182

                item.Property.Rename("person." + item.Path);

            }

            var json = jObject.ToString();

            Console.WriteLine(json);

            Assert.IsTrue(JToken.DeepEquals(JToken.Parse(GetRequiredJson()), jObject));

        }   

        static string GetRequiredJson() => @"{

   ""person.firstName"":""Homer"",

   ""person.lastName"":""Simpson"",

   ""person.address"":{

      ""person.address.street"":""Evergreen Terrace"",

      ""person.address.streetNumber"":""742""

   }

}";

    }

​

    public class Program

    {

        public static void Main()

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Assembly.GetName().Name,  typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                TestClass.Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.Location.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​